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An efficient one-pot method for the synthesis of organic disulfides from aryl and alkyl halides and potassium sulfide has been described. K2S acts as an inexpensive and readily available sulfur source. A variety of symmetric diaryl and dialkyl disulfides was prepared in good to excellent yields using NiCl2·6H2O and acetylacetone as the catalytic system. | non-battery |
Electrodeposited crystalline Cu2Sb thin films are studied to evaluate the use of these electrodes as model systems for studying Cu2Sb as a lithium ion battery anode material. The films have been characterized with an emphasis on determining the film quality and relating the structure, composition, and morphology to the resulting electrochemical and morphological transformations that occur during electrochemical lithiation and delithiation. It is shown that electrodeposition can produce high quality films that are devoid of major defects and can be used to provide mechanistic insight on the electrochemistry of reversible lithium alloying. The CuxSb films show that the fundamental reaction mechanism remains largely unchanged for copper concentrations of 1>x>3. For the first time we show that the copper concentration greatly affects critical criteria for anode materials such as the initial coulombic efficiency and reversible capacity of the electrode material. Voltage limit experiments show that an overpotential is required to remove trapped lithium states. Additional ex-situ experiments reveal that internal strain created during the lithiation process is relieved by buckling, greatly altering the film surface area and geometry, and resulting in the formation of cracks upon delithiation. This process is only semi-reversible, and strained areas remain visible even when discharged outside the voltage window of Cu2Sb determined by differential capacity plots. The results presented here indicate that these electroplated thin films are useful as analytical tools for showing pathways to improving the performance and fundamental understanding of alloy based lithium-ion battery anodes. | battery |
Two types of ultracapacitor modules have been developed for use as energy-storage devices for 42-V systems in automobiles. The modules show high performance and good reliability in terms of discharge and recharge capability, long-term endurance, and high energy and power. During a 42-V system simulation test of 6-kW power boosting/regenerative braking, the modules demonstrate very good performance. In high-power applications such as 42-V and hybrid vehicle systems, ultracapacitors have many merits compared with batteries, especially with respect to specific power at high rate, thermal stability, charge–discharge efficiency, and cycle-life. Ultracapacitors are also very safe, reliable and environmentally friendly. The cost of ultracapacitors is still high compared with batteries because of the low production scale, but is decreasing very rapidly. It is estimated that the cost of ultracapacitors will decrease to US$ 300 per 42-V module in the near future. Also, the maintenance cost of the ultracapacitor is nearly zero because of its high cycle-life. Therefore, the combined cost of the capacitor and maintenance will be lower than that of batteries in the near future. Overall, comparing performance, price and other parameters of ultracapacitors with batteries, ultracapacitors are the most likely candidate for energy-storage in 42-V systems. | battery |
We examined the stability of and cross-influences between externalizing behaviors and intervention engagement among children participating in a randomized clinical trial of an intervention for disruptive behavioral youth. Analyses also accounted for the influence of caregiver depression, family relationship quality, and sociodemographic factors (race, income) on the relationship between behaviors and intervention engagement. Analyses were based on 118 children participating in the Coping Power intervention. Composite variables were created to represent externalizing behaviors and intervention engagement constructs. Associations between these composite variables were examined over 24 treatment sessions. Findings indicated a regressive relationship among externalizing behaviors, i.e., baseline externalizing behaviors were positively associated with immediate follow-up behaviors. There were also dynamic relationships observed among engagement constructs. Notably, engagement with in-session activities during sessions 1–8 was positively associated with out-of-session activity engagement during the same treatment time period. Engagement with out-of-session activities during sessions 1–8 was positively associated with in-session activity engagement during sessions 9–16, indicating a complete mediation between early and middle in-session engagement through the mechanism of early out-of-session engagement. A crosslag relationship was observed: middle in-session engagement was negatively associated with externalizing behaviors at immediate follow-up. Finally, an interaction of race by income on immediate follow-up externalizing behaviors was observed, such that Black children’s externalizing behaviors remain static regardless of income level while White children’s behaviors decreased with higher income. Our findings support the contention that focusing on intervention engagement may be especially important in prevention interventions.
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Drawing from the dual process model of morality and life history theory, the present research examined the role of cognitive and emotional processes as bridges between basic environmental challenges (i.e., unpredictability and competition) and other-centered moral orientation (i.e., prioritizing the welfare of others). In two survey studies, cognitive and emotional processes represented by future-oriented planning and emotional attachment, respectively (Study 1, N = 405), or by perspective taking and empathic concern, respectively (Study 2, N = 424), positively predicted other-centeredness in prosocial moral reasoning (Study 1) and moral judgment dilemmas based on rationality or intuition (Study 2). Cognitive processes were more closely related to rational aspects of other-centeredness, whereas the emotional processes were more closely related to the intuitive aspects of other-centeredness (Study 2). Finally, the cognitive and emotional processes also mediated negative effects of unpredictability (i.e., negative life events and childhood financial insecurity), as well as positive effects of individual-level, contest competition (i.e., educational and occupational competition) on other-centeredness. Overall, these findings support the view that cognitive and emotional processes do not necessarily contradict each other. Rather, they might work in concert to promote other-centeredness in various circumstances and might be attributed to humans’ developmental flexibility in the face of environmental challenges. | non-battery |
The electrochemistry of superdense ‘LiC2’ prepared by ball-milling has been investigated in EC-DMC solutions 1 M LiClO4. A primary capacity very close to 1115 mAhg−1 per carbon atom was observed during the first deintercalation cycle at constant current. The following intercalation–deintercalation cycles yielded capacity close to the theoretical value of 372 mAhg−1, typical of natural graphite. Electrochemical ac-impedance spectroscopy demonstrates that a solid electrolyte interface (SEI) is formed spontaneously upon immersion of the electrode in the electrolyte. Due to the complex nature of the compound prepared by ball-milling (a mixture of lithium metal, LiC3 and LiC6) the mechanism of the first deintercalation is rather complex. It involves the oxidation of lithium metal at about 22 mV versus Li, followed by the decomposition of the superdense phase LiC3 and of LiC6 at potentials that corresponds to the normal electrochemical lithium deintercalation from LiC6. Lithium metal in ‘LiC2’ easily reacts with nitrogen to yield α-Li3N that irreversibly de-intercalates about 1.8±0.1 lithium before decomposing. | battery |
New Li-ion cells are formed by combining a LiFe0.25Mn0.5Co0.25PO4 olivine cathode either with Sn-Fe2O3-C or with Sn-C composite anodes. These active materials exhibit electrochemical properties very attractive in view of practical use, including the higher working voltage of the LiFe0.25Mn0.5Co0.25PO4 cathode with respect to conventional LiFePO4, as well as the remarkable capacity and rate capability of Sn-Fe2O3-C and Sn-C anodes. The stable electrode/electrolyte interfaces, demonstrated by electrochemical impedance spectroscopy, along with proper mass balancing and anode pre-lithiation, allow stable galvanostatic cycling of the full cells. The two batteries, namely Sn-Fe2O3-C/LiFe0.25Mn0.5Co0.25PO4 and Sn-C/LiFe0.25Mn0.5Co0.25PO4, reversibly operate revealing promising electrochemical features in terms of delivered capacity, working voltage and stability, thus suggesting these electrodes combinations as suitable alternatives for an efficient energy storage. | battery |
The electrochemical synthesis of a copolymer electrolyte (PEO-PMMA) into titania nanotubes is described and studied. Compared with the electrochemical systems based on solid electrolytes deposited by top-down techniques, the copolymer/titania nanotube material reveals high electrochemical performance, opening new perspectives for the fabrication of 3D all-solid-state microbatteries. | non-battery |
The proton insertion/deinsertion behavior of γ-MnO2 samples of various oxygen contents and various structural parameters has been studied. The analysis of the voltammograms observed during the discharges and charges of the different samples is presented, and leads to a classification of the samples according to their structural parameters. The proton insertion capacities and the cycling properties of the different samples have been compared and correlated to their structural properties. | battery |
TiSnSb shows an excellent behavior as negative electrode for Li-ion batteries. However the role of Ti is still unclear in the mechanism. To better understand the role played by the transition metal on both the mechanism and the performance of TiSnSb, a progressive substitution of Ti by Nb has been achieved. A full study focuses on the electrochemical mechanisms of the Ti1−y Nb y SnSb system with 0 ≤ y ≤ 1 vs Li by combining in situ XRD and Mössbauer, and EXAFS analyses. The electrochemical mechanism is found to be a reversible conversion mechanism: MSnSb + 7Li ↔ Li3Sb + 1/2 Li7Sn2 + M0. The lithium is found to react simultaneously with both Sn and Sb. Nb-rich alloys have been found also to be very promising negative electrode demonstrating the versatility of the MSnSb electrode material family for Li-ion battery application. Using the appropriate electrode formulation, the good cycling life of TiSnSb is not affected by its substitution by Nb. | battery |
A physics-based Li-ion battery (LIB) aging model accounting for both lithium plating and solid electrolyte interphase (SEI) growth is presented, and is applied to study the aging behavior of a cell undergoing prolonged cycling at moderate operating conditions. Cell aging is found to be linear in the early stage of cycling but highly nonlinear in the end with rapid capacity drop and resistance rise. The linear aging stage is found to be dominated by SEI growth, while the transition from linear to nonlinear aging is attributed to the sharp rise of lithium plating rate. Lithium plating starts to occur in a narrow portion of the anode near the separator after a certain number of cycles. The onset of lithium plating is attributed to the drop of anode porosity associated with SEI growth, which aggravates the local electrolyte potential gradient in the anode. The presence of lithium metal accelerates the porosity reduction, further promoting lithium plating. This positive feedback leads to exponential increase of lithium plating rate in the late stage of cycling, as well as local pore clogging near the anode/separator interface which in turn leads to a sharp resistance rise. | battery |
LiMn2O4 and LiCu x Al y Mn2 − x − y O4 (x =0.50; y =0.05–0.50) powders have been synthesized via sol–gel method for the first time using Margaric acid as chelating agent. The synthesized samples have been used to physical and electrochemical characterization such as thermo gravimetric analysis (TG/DTA), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and electrochemical characterization viz., electrochemical galvanostatic cycling studies, electrochemical impedance spectroscopy (EIS) and differential capacity curves (dQ/dE). XRD patterns of LiMn2O4 and LiCu x Al y Mn2 − x−y O4 confirm high degree of crystallinity with better phase purity of synthesized materials. FESEM images of parent LiMn2O4 depict the most of the particles that are in 0.5μm while LiCu0.5Al0.05Mn1.45O4 powders exhibiting ice-cube surface morphology with good agglomerated less particle size of 50nm. TEM images of spinel LiMn2O4 and LiCu0.5Al0.05Mn1.45O4 corroborate that all the synthesized particles are nano-sized with uniform spherical and cloudy particle morphology. LiMn2O4 samples calcined at 850°C deliver the high discharge capacity of 130mAhg−1 in the first cycle while LiCu0.5Al0.05Mn1.45O4 samples deliver 120mAhg−1 during the first cycle. Inter alia all the dopant compositions investigated, LiCu0.5Al0.05Mn1.45O4 delivers the stable cycling performance of 119 and 115mAhg−1 in the 5th and 10th cycle with low capacity fade of 0.1 and 0.1mAhg−1 cycle−1 corresponding to columbic efficiency of 99 and 99%. | battery |
Cobalt–nickel layered double hydroxides (Co x Ni1−x LDHs) were deposited onto stainless steel electrodes by the potentiostatic deposition method at −1.0V vs. Ag/AgCl using various molar ratios of Co(NO3)2 and Ni(NO3)2 in distilled water. Their structure and surface morphology were studied by using X-ray diffraction analysis, energy dispersive X-ray spectroscopy and scanning electron microscopy. A network of Co x Ni1−x LDH nanosheets was obtained. The nature of the cyclic voltammetry and charge–discharge curves suggested that the Co x Ni1−x LDHs exist in the form of solid solutions. The capacitive characteristics of the Co x Ni1−x LDHs in 1M KOH electrolyte showed that Co0.72Ni0.28 LDHs had the highest specific capacitance value, 2104Fg−1, which is also the highest yet reported value for oxide materials in general. | battery |
In the present paper, the composition of several spinel-type λ-MnO2 samples (which absorb lithium ions with a high selectivity in an aqueous solution) is analyzed and the correlation between the composition and the absorption capacity of lithium is investigated experimentally. Then samples of λ-MnO2 with different hydrogen contents are prepared, and each lithium absorption capacity is measured. The results indicate that the absorption capacity of lithium is proportional to the content of hydrogen ions with the ability to ion exchange. Furthermore, it is concluded that the reason for the selective absorption of lithium ions in λ-MnO2 is not based upon the so-called ion sieve effect emphasized conventionally, but is based upon a proper ion exchange reaction which occurs only between lithium and hydrogen ions. | battery |
Neuropsychological evaluation of a patient's cognitive capabilities before and after epilepsy surgery is essential in elective epilepsy surgery. On the one hand, neuropsychology provides accessory information regarding the localization and lateralization of epilepsy-associated cognitive impairment; on the other hand, it is a useful tool for quality and outcome control of epilepsy surgery which helps to make surgery more effective and safe. Evaluation of the adequacy of the brain tissues to be resected and of the patient's mental reserve capacities allows for a prediction of the postoperative cognitive development. Successful surgery can stop mental decline due to chronic epilepsy and it can reverse this negative trend by release of functions and capacities that were secondarily affected before surgery. However, surgery bears the risk of additional impairments which, in interaction with normal or even pathological processes of mental aging, may accelerate cognitive decline at an older age. From a neuropsychological point of view, early recognition of pharmacoresistance is important along with early and complete seizure control with maximal sparing of functional tissues. | non-battery |
Strength-based parenting (SBP) is a style of parenting characterized by knowledge and encouragement of a child’s unique personality, abilities, talents, and skills (i.e., strengths). Recent studies have demonstrated a unique contribution of SBP, above other parenting styles, in predicting a range of wellbeing indicators in adolescents. Given that wellbeing supports learning, and SBP predicts wellbeing, it is also plausible that adolescents with strength-based parents will have greater academic achievement. At the beginning of term, students from a public secondary school in Australia (N = 741, Mage = 13.70, SD = 1.33; 50% female) completed a self-report survey measuring perceptions of parental style, engagement, and perseverance. Subsequent academic results were obtained 3 months later. SBP predicted higher wellbeing in the form of adolescent engagement and perseverance. SBP also demonstrated a significant effect on academic achievement which was mediated by perseverance, but not engagement. Thus, results supported a model in which adolescents with strength-based parents achieved higher grades via increased perseverance. Results reaffirm the importance of the parent-student link, and dispositional qualities of engagement and perseverance, in predicting educational outcomes such as grades. This study extends positive education research beyond the classroom by demonstrating that positive parenting techniques like SBP can predict student wellbeing and academic achievement.
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This paper presents data on widespread abnormal accumulations in coal deposits of some rare metal(loid)s (Ge, Ga, Se, Li and REE+Y), which play a key role in energy-efficient technologies and alternative power development. It is shown that enrichment of these metal(loid)s may occur in coal seams in host- and basement-rocks of coal basins at comparable concentrations to those in conventional ores. Genesis of high concentrations of the rare metal(loid)s and their modes of occurrence in coal basins are reviewed. Moreover, utilization prospects of these metal(loid)s as byproduct coal deposits are evaluated. The extraction of these metal(loid) resources during coal exploitation and utilization would not only increase beneficial use of coal deposits themselves but also promote humanity’s further movement on the “green road”. | non-battery |
Rechargeable lithium-ion batteries (LIBs) afford a profound impact on our modern daily life. However, LIBs are approaching the theoretical energy density, due to the inherent limitations of intercalation chemistry; thus, they cannot further satisfy the increasing demands of portable electronics, electric vehicles, and grids. Therefore, battery chemistries beyond LIBs are being widely investigated. Next-generation lithium (Li) batteries, which employ Li metal as the anode and intercalation or conversion materials as the cathode, receive the most intensive interest due to their high energy density and excellent potential for commercialization. Moreover, significant progress has been achieved in Li batteries attributed to the increasing fundamental understanding of the materials and reactions, as well as to technological improvement. This review starts by summarizing the electrolytes for next-generation Li batteries. Key challenges and recent progress in lithium-ion, lithium–sulfur, and lithium–oxygen batteries are then reviewed from the perspective of energy and chemical engineering science. Finally, possible directions for further development in Li batteries are presented. Next-generation Li batteries are expected to promote the sustainable development of human civilization. | non-battery |
Major aspects related to lithium deposition in lithium-ion and lithium metal secondary batteries are reviewed. For lithium-ion batteries with carbonaceous anode, lithium deposition may occur under harsh charging conditions such as overcharging or charging at low temperatures. The major technical solutions include: (1) applying electrochemical models to predict the critical conditions for deposition initiation; (2) preventions by improved battery design and material modification; (3) applying adequate charging protocols to inhibit lithium deposition. For lithium metal secondary batteries, the lithium deposition is the inherent reaction during charging. The major technical solutions include: (1) the use of mechanistic models to elucidate and control dendrite initiation and growth; (2) engineering surface morphology of the lithium deposition to avoid dendrite formation via adjusting the composition and concentration of the electrolyte; (3) controlling battery working conditions. From a survey of the literature, the areas that require further study are proposed; e.g., refining the lithium deposition criteria, developing an effective AC self pre-heating method for low-temperature charging of lithium-ion batteries, and clarifying the role the solid electrolyte interphase (SEI) plays in determining the deposition morphology; to facilitate a refined control of the lithium deposition. | battery |
Hydrogen is a promising vector in the decarbonization of energy systems, but more efficient and scalable synthesis is required to enable its widespread deployment. Towards that aim, Serra et al. present a microwave-based approach that allows contactless water electrolysis that can be integrated with hydrocarbon production.
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Floating photovoltaic (FPV) systems are an emerging technology suitable for large plants, especially, on fresh water basins. We suggest integrating a CAES system to FPV using the pipes, necessary for the buoyancy of the modular raft structure, as a compressed air reservoir. The huge basin thermal inertia allows for an isothermal compression– expansion cycle, which promises high storage efficiency. | battery |
The genotoxic potential of two products of multi-walled carbon nanotubes (coded as N-MWCNTs, diameter of 44nm/BET surface area of 69m2/g and MWNT-7, diameter of 70nm/BET surface area of 23m2/g) was evaluated using a battery of genotoxicity assays, comprising a bacterial reverse mutation test, an in vitro mammalian chromosomal aberration test, and a mammalian erythrocytes micronucleus test. Neither type exerted mutagenicity in Salmonella typhimurium TA98, TA100, TA1535, and TA1537, or in Escherichia coli WP2uvrA, in the absence or presence of metabolic activation. The products of MWCNTs did not increase the number of structural chromosomal aberrations either, regardless of metabolic activation, though they increased the number of numerical chromosomal aberrations, one slightly and the other distinctly, in the absence of metabolic activation. In ICR mice, the two products did not affect the proportion of immature erythrocytes, the total proportion of erythrocytes, or the number of micronuclei in immature erythrocytes. | non-battery |
Binder, one of the most important battery components, plays a critical role in lithium–sulfur batteries. Poly(vinylidene difluoride) (PVDF), a commonly used binder in lithium–sulfur batteries, does not have a strong affinity to the intermediate polysulfides, however, leading to fast capacity fading with electrochemical cycling. Herein, copolymers of vinylidene difluoride with other monomers are used as multi-functional binders to enhance the electrochemical performance of lithium–sulfur batteries. Compared to the PVDF, the copolymer, poly(vinylidene difluoride-trifluoroethylene) (P(VDF-TRFE)) binder exhibits higher adhesion strength, less porosity, and stronger chemical interaction with polysulfides, which helps to keep the polysulfides within the cathode region, thereby improving the electrochemical performance of the lithium–sulfur battery. As a result, sulfur electrode with P(VDF-TRFE) binder delivered a high capacity of 801mAhg−1 at 0.2C after 100 cycles, which is nearly 80% higher capacity than the corresponding sulfur cathode with PVDF binder. | battery |
The electronic structural changes during lithium-ion intercalation/de-intercalation process of nickel substituted lithium manganese spinel oxides have been investigated by using X-ray absorption near-edge structure (XANES) spectra of O K-edges as well as Ni L3-edges and Mn L3-edges. The results of the XANES spectra indicate that the electronic structure of both manganese and oxygen atoms contribute on the redox reaction at 0.06 ≤ x < 1, and only that of nickel atom affect the redox reaction at 1 < x ≤ 1.78 in Li x Ni0.5Mn1.5O4. Thus, the electronic structural change of oxygen atom is also crucial for considering redox reaction at intercalation/de-intercalation process, and the contribution of the oxygen atom on redox reaction differs in various redox cation species. | battery |
As the cooling energy demand in buildings is set to increase dramatically in the future, the exploitation of passive solutions like natural ventilation could prove vital in reducing the reliance on mechanical systems. Models that can predict air temperature accurately in naturally ventilated mode are key to understanding the potential of natural ventilation now and in the future. This article presents a simulation based case study of a retrofitted nearly zero energy test-bed university building, in naturally ventilated mode only. The study had three aims: (1) calibration and validation of a whole building energy model, (2) a comparative analysis of occupancy schedules and opening control strategies, and (3) a comparison of researcher and practitioner approaches. Results showed the detailed building model was capable of predicting room level air temperature with a low level of error (0.27 °C ≤ RMSE ≤ 1.50 °C) that was well within the limits of existing calibration standards (MBE ±10%, CVRMSE <20%). The comparative analysis highlighted the need to consider occupancy schedules that have a wide range of diversity, and opening control strategies that reflect the manual and automated relationship in natural ventilation systems. The approach comparison highlighted that both practitioner and researcher approaches to simulating both occupancy schedules and opening control strategies showed similar levels of performance for the application considered. The paper also provides recommendations for those modelling air temperatures and thermal comfort in nearly zero energy buildings. | battery |
The electrochemical lithium insertion into a-Si:H thin-film electrodes, CVD-grown on stainless-steel substrates at 100 and 250°C, is studied using chronopotentiometry, cyclic voltammetry, and electrochemical impedance spectroscopy. It is shown that the discharge capacity of the films deposited at 250°C is higher than that of the equally thick films deposited at 100°C. For the films deposited at 250°C, the dependence of their discharge capacity on the thickness is found. The increase in the film thickness involves a more drastic decrease of the discharge capacity during the potential cycling; in particular, for the 0.25μm- and 1.35μm-thick films, their discharge capacity at a current density of 0.175mA/cm2 in the 3rd cycle is ∼2 Ah/g; in the 100th cycle, 1.10 and 0.37Ah/g, respectively. An equivalent circuit is suggested for the lithium insertion to the electrodes, which comprises the electrolyte resistance and three RC-chains in series, each chain being a parallel connection of a resistance and a constant-phase element, which relate to charge transfer at the silicon/electrolyte interface, charge transport in the passive film on silicon, and the lithium diffusion into the silicon bulk. With the potential cycling in progress, the most significant changes are observed in the chain relating to the passive film. The Li diffusion coefficient in a-Si:H is estimated as 10−13 cm2/s. | battery |
An initial study of a non-precious metal based bifunctional oxygen electrode for use in regenerative fuel cells with alkaline anion exchange membranes is described. Four nanometer size Cu x Mn0.9−x Co2.1O4 samples (x =0, 0.3, 0.6, and 0.9) were prepared and characterized with XRD, SEM, TEM, and cyclic voltammetry. The Cu x Mn0.9−x Co2.1O4 samples exhibited promising ORR and OER catalytic activities. The gap between ORR half wave potentials of Pt/C and Cu x Mn0.9−x Co2.1O4 in 1M KOH achieved only 50mV. The onset potentials for OER on Cu x Mn0.9−x Co2.1O4 catalysts were more than 100mV more negative than Pt/C in 1M KOH. MEA with Cu x Mn0.9−x Co2.1O4 bifunctional oxygen electrode was prepared with CCM method and applied in a laboratory scale regenerative fuel cell. In fuel cell mode the peak power density was over 80mWcm−2 and in electrolyser mode the onset voltage was about 1.55V. The fuel cell to electrolyser voltage ration at 100mAcm−2 achieved c.a. 31.87%. | battery |
The effects of temperatures in the range of −20 °C to 70 °C on the ageing behaviour of cycled Lithium-ion batteries are investigated quantitatively by electrochemical methods and Post-Mortem analysis. Commercial 18650-type high-power cells with a Li x Ni1/3Mn1/3Co1/3O2/Li y Mn2O4 blend cathode and graphite/carbon anode were used as test system. The cells were cycled at a rate of 1 C until the discharge capacity falls below 80% of the initial capacity. Interestingly, an Arrhenius plot indicates two different ageing mechanisms for the ranges of −20 °C to 25 °C and 25 °C to 70 °C. Below 25 °C, the ageing rates increase with decreasing temperature, while above 25 °C ageing is accelerated with increasing temperature. The aged 18650 cells are inspected via scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), inductively coupled plasma (ICP), measurements of electrode thickness and X-ray diffraction (XRD) after disassembly to learn more about the chemical reasons of the degradation. The effect of different temperatures on the electrode polarizations are evaluated by assembling electrodes in pouch cells with reference electrode as a model system. We find that the dominating ageing mechanism for T < 25 °C is Lithium plating, while for T > 25 °C the cathodes show degeneration and the anodes will be increasingly covered by SEI layers. | battery |
Neurocognitive enhancement therapy (NET) is a remediation program for the persistent and function-limiting cognitive impairments of schizophrenia. In a previous study in veterans, NET improved work therapy outcomes as well as executive function and working memory. The present study aimed to determine whether NET could enhance functional outcomes among schizophrenia and schizoaffective patients in a community mental health center receiving community-based vocational services. Method: Patients (N =72) participated in a hybrid transitional and supported employment program (VOC) and were randomized to either NET+VOC or VOC only. NET+VOC included computer-based cognitive training, work feedback and a social information information-processing group. VOC only also included two weekly support groups. Active intervention was 12 months with 12 month follow-up. Follow-up rate was 100%. Results: NET+VOC patients worked significantly more hours during the 12 month follow-up period, reached a significantly higher cumulative rate of competitive employment by the sixth quarter, and maintained significantly higher rates of employment. Conclusion: NET training improved vocational outcomes, suggesting the value of combining cognitive remediation with other rehabilitation methods to enhance functional outcomes. | non-battery |
As Europe moves towards renewable energy, hydropower stands out as a renewable technology that can provide supply side flexibility through dispatchable electricity production. Several studies have investigated the flexibility hydropower can provide with a particular focus on the Nordic hydropower resources. Of all European countries, Norway has the largest hydropower resources and storage capacity. However, Norway also has a highly electrified heating sector, which means high electricity demand during winter when reservoirs are low. This paper uses EnergyPLAN to analyse how a shift from individual electric heating to district heating affects the flexibility the Norwegian energy system can provide to Europe. The analysis develops a 2015 reference scenario and two scenarios that introduce district heating based on biomass and heat pumps, respectively. Results show that district heating can decrease the maximum load on dammed hydropower facilities, thus freeing up capacity for potential export. Furthermore, the dammed hydropower facilities are able to balance the electricity demands in all hours of the year. However, the shift to district heating also increases forced export to drain reservoirs as domestic electricity demand is reduced. Also, the amount of import the system is able to handle is decreased under the modelled conditions. | battery |
We propose a novel low-cost synthesis method of a LiFePO4/C composite with excellent battery performances that combine high-frequency induction heating with carbothermal reduction. Our method uses a very inexpensive Fe2O3 as a Fe source. The LiFePO4/C is synthesized in far less time (within a few minutes) at 900 °C than in a conventional method. Although the initially synthesized LiFePO4/C (LFP-120) contains such over-reduction impurities as Fe2P or Fe3P, optimized LiFePO4/C (LFP-90) containing no impurities is obtained by adjusting the heating time. Moreover, the primary particle size of the LFP-90 is sufficiently small to achieve fast Li-ion diffusion. The cathode containing LFP-90 has good charge–discharge rate performance and shows discharge capacities of 153.3 and 100.1 mAh g−1 at 1/10 and 10C-rates. The cathode with LFP-90 has excellent cycle stability and shows no degradation after high-rate charge–discharge tests. Our method reasonably reduces the manufacturing cost of LiFePO4/C. | battery |
Excitotoxicity underlies neuronal death in many neuropathological disorders, such as Alzheimer’s disease and multiple sclerosis. In murine models of these diseases, disruption of CX3CR1 signaling has thus far generated data either in favor or against a neuroprotective role of this crucial regulator of microglia and monocyte functions. In this study, we investigated the recruitment of circulating PU.1-expressing cells following sterile excitotoxicity and delineated the CX3CR1-dependent neuroprotective functions of circulating monocytes versus that of microglia in this context. WT, Cx3cr1-deficient and chimeric mice were subjected to a sterile excitotoxic insult via an intrastriatal injection of kainic acid (KA), a conformational analog of glutamate. Following KA administration, circulating monocytes physiologically engrafted the brain and selectively accumulated in the vicinity of excitotoxic lesions where they gave rise to activated macrophages depicting strong Iba1 and CD68 immunoreactivity 7 days post-injury. Monocyte-derived macrophages completely vanished upon recovery and did thus not permanently seed the brain. Furthermore, Cx3cr1 deletion significantly exacerbated neuronal death, behavioral deficits and activation of microglia cells following sterile excitotoxicity. Cx3cr1 disruption also markedly altered the blood levels of patrolling monocytes 24 h after KA administration. The specific elimination of patrolling monocytes using Nr4a1−/− chimeric mice conditioned with chemotherapy provided direct evidence that these circulating monocytes are essential for neuroprotection. Taken together, these data support a beneficial role of CX3CR1 signaling during excitotoxicity and highlight a novel and pivotal role of patrolling monocytes in neuroprotection. These findings open new research and therapeutic avenues for neuropathological disorders implicating excitotoxicity.
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Ni–MH spent batteries are heterogeneous and complex materials, so any kind of metallurgical recovery process needs a mechanical pre-treatment at least to separate irony materials and recyclable plastic materials (like ABS) respectively, in order to get additional profit from this saleable scrap, as well as minimize waste arising from the braking separation process. Pyrometallurgical processing is not suitable to treat Ni–MH batteries mainly because of Rare Earths losses in the slag. On the other hand, the hydrometallurgical method, that offers better opportunities in terms of recovery yield and higher purity of Ni, Co, and RE, requires several process steps as shown in technical literature. The main problems during leach liquor purification are the removal of elements such as Mn, Zn, Cd, dissolved during the leaching step, and the separation of Ni from Co. In the present work, the latter problem is overcome by co-deposition of a Ni-35÷40%w Co alloy of good quality. The experiments carried out in a laboratory scale pilot-plant show that a current efficiency higher than 91% can be reached in long duration electrowinning tests performed at 50 °C and 4.3 catholyte pH. | non-battery |
The cause of the thermal runaway problem in lithium-ion batteries problem is still unclear. This bottle neck has prevented increases in the energy density of lithium-ion batteries, of which the technology may stagnate for many years. The diversity of cell chemistries makes this problem more difficult to analyze. This paper reports work conducted by Tsinghua University and its collaborators into the establishment of a thermal analysis database. The database contains comparable data for different kinds of cells using accelerating rate calorimetry and differential scanning calorimetry. Three characteristic temperatures are summarized based on the common features of the cells in the database. In attempting to explain the mechanisms that are responsible for the characteristic temperature phenomena, we have gained new insight into the thermal runaway mechanisms of lithium-ion batteries. The results of specially designed tests show that the major heat source during thermal runaway for cells with Li(NixCoyMnz)O2 cathode and carbon-based anode is the redox reaction between the cathode and anode at high temperature. In contrast to what is commonly thought, internal short circuits are responsible for very little of the total heat generated during thermal runaway, although they contribute to triggering the redox reactions after the separator collapses. The characteristic temperatures provide comparable parameters that are useful in judging the safety of a newly designed battery cell. Moreover, the novel interpretation of the thermal runaway mechanism provide guidance for the safety modelling and design of lithium-ion batteries. | battery |
Unknown Page numbers followed by f indicate figures; t, tables. | non-battery |
Various Ni-rich layered oxide cathodes (above 0.80 Ni content), such as LiNi1−y−zCoyAlzO2 (NCA), are used in electric vehicles (EVs) due to their high capacity (∼200 mAh g−1 for NCA). However, to improve cycle performance and thermal stability and to ensure longer and safer usage, numerous studies have investigated surface modification, coating, and doping of cathode materials. In this study, we have investigated the characteristics of Li[Ni0.85CoxMn0.15−x]O2 with various Mn to Co ratios (x = 0–0.15) synthesized by a coprecipitation method. The discharge capacities of the Li[Ni0.85CoxMn0.15−x]O2 cathodes are similar at around 206 mAh g−1 at room temperature and 213.8 mAh g−1 at 55 °C between 2.7 and 4.3 V at a 0.2C rate, while the cyclability, thermal stability, and rate capability of all samples differ according to the Mn and Co ratio. The Li[Ni0.85Co0.05Mn0.10]O2 cathode shows the most promising electrochemical properties under different conditions among the various cathodes evaluated; it displays a high rate capacity (approximately 163 mAh g−1 at 5C rate) at 25 °C and good thermal stability (main exothermic temperature of 233.7 °C and relatively low heat evolution of 857.3 J g−1). | battery |
With constructions of demonstrative microgrids, the realistic optimal economic dispatch and energy management system are required eagerly. However, most current works usually give some simplifications on the modeling of microgrids. This paper presents an optimal day-ahead scheduling model for a microgrid system with photovoltaic cells, wind turbine units, diesel generators and battery storage systems. The power flow constraints are introduced into the scheduling model in order to show some necessary properties in the low voltage distribution network of microgrids. Besides a hybrid harmony search algorithm with differential evolution (HSDE) approach to the optimization problem is proposed. Some improvements such as the dynamic F and CR, the improved mutation, the additional competition and the discrete difference operation have been integrated into the proposed algorithm in order to obtain the competitive results efficiently. The numerical results for several test microgrids adopting the IEEE 9-bus, IEEE 39-bus and IEEE 57-bus systems to represent their transmission networks are employed to show the effectiveness and validity of the proposed model and algorithm. Not only the normal operation mode but also some typical fault modes are used to verify the proposed approach and the simulations show the competitiveness of the HSDE algorithm. | battery |
A hierarchically porous NiO film on nickel foam substrate is prepared by a facile ammonia-evaporation method. The self-assembled film possesses a structure consisting of NiO triangular prisms and randomly porous NiO nanoflakes. The pseudocapacitive behaviors of the porous NiO film are investigated by cyclic voltammograms and galvanostatic charge–discharge tests in 1M KOH. The hierarchically porous NiO film exhibits a high discharge capacitance and excellent rate capability with 232Fg−1, 229Fg−1, 213Fg−1 and 200Fg−1 at 2, 4, 10, and 20Ag−1, respectively. The specific capacitance of 87% is maintained from 2Ag−1 to 20Ag−1. The porous NiO film also shows rather good cycling stability and exhibits a specific capacitance of 348Fg−1 after 4000 cycles. | battery |
Despite the promising future of lithium-oxygen (Li-O2) battery in replacing conventional lithium ion battery for high-energy applications, the complicated reaction mechanisms determining the sluggish discharge-charge kinetics have not been fully understood. Here, utilizing in situ liquid transmission electron microscopy, the (electro)chemical fundamentals in a working Li-O2 battery is explored. During discharge, the nucleation of Li2O2 is observed at the carbon electrode/electrolyte interface, and the following growth process exhibits Li+ diffusion-limited kinetics. Nucleation and growth of Li2O2 are also observed within the electrolyte, where there is no direct contact with the carbon electrode indicating the existence of non-Faradaic disproportionation reaction of intermediate LiO2 into Li2O2. The growth of Li2O2 isolated in the electrolyte exhibits O2 - diffusion-limited kinetics. Li2O2 at the carbon electrode surface and isolated in the electrolyte are both active upon charging and gradually decomposed. For Li2O2 particles rooted at the carbon electrode surface, the decomposition starts at the electrode/Li2O2 interface indicating electron-conduction limited charge kinetics. For Li2O2 isolated within the electrolyte, surprisingly, a side-to-side decomposition mode is identified indicating the non-Faradaic formation of dissolvable O2 -, whose diffusion in the electrolyte controls the overall charge kinetics. This work reveals further details of underlying mechanisms in a working Li-O2 battery and identifies various limiting factors controlling the discharge and charge processes. | battery |
In this contribution, we focus on propylene carbonate (PC)-based electrolytes for lithium-ion batteries. In order to avoid solvent co-intercalation into graphite the presence of a solid electrolyte interphase (SEI) is required. This film is formed due to a film-forming species, i.e. a film-forming electrolyte additive. In this contribution, we focus on a vinylene compound, 2-cyanofuran (2CF) which proves to perform well in propylene carbonate electrolytes. 2CF is investigated by in situ Fourier transform infrared (FTIR) spectroscopy in a specially developed IR cell. We conclude that the cathodic reduction of the vinylene groups (=via reduction of the double bond) in the electrolyte additive is the initiating, and thus an important step of the SEI formation process. The possibility of an electropolymerization reaction of the vinylene monomers in the used electrolytes is critically discussed on the basis of the obtained IR data. | battery |
A novel hydrothermal synthesis was developed to prepare carbon-coated lithium vanadium phosphate (Li3V2(PO4)3) powders to be used as cathode material for Li-ion batteries. The structural, morphological and electrochemical properties were investigated by means of X-ray powder diffraction (XRD), thermogravimetry (TG), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and constant current charge–discharge cycling. This material exhibits high initial discharge capacity of 178, 173 and 172mAhg−1 at 0.1, 0.2 and 0.5 C between 3.0 and 4.8V, respectively. Moreover, it displays good fast rate performance, which discharge capacities of 136, 132 and 127mAhg−1 can be delivered after 100 cycles between 3.0 and 4.8V versus Li at a different rate of 1, 2 and 5 C, respectively. For comparison, the electrochemical properties of carbon-coated lithium vanadium phosphate prepared by traditional solid-state reaction (SSR) method are also studied. | battery |
We present the first results of the nuclear magnetic relaxation dispersion (NMRD) of the confined proton-bearing cation (BMI) and fluorine-bearing anion (TFSI) pair of ionic liquids (Li+-ionogels) confined within a silica-like mesoporous matrices designed for lithium batteries. These results are in favour of a very-correlated dynamical motion of the anion–cation pair within the solid and disordered silica matrix. | non-battery |
Patch clamp electrophysiology serves as a powerful method for studying changes in plasma membrane ion conductance induced by externally applied high-intensity nanosecond electric pulses (NEPs). This paper describes an enhanced monitoring technique that minimizes the length of time between pulse exposure and data recording in a patch-clamped excitable cell. Whole-cell membrane currents were continuously recorded up to 11 ms before and resumed 8 ms after delivery of a 5-ns, 6 MV/m pulse by a pair of tungsten rod electrodes to a patched adrenal chromaffin cell maintained at a holding potential of −70 mV. This timing was achieved by two sets of relay switches. One set was used to disconnect the patch pipette electrode from the pre-amplifier and connect it to a battery to maintain membrane potential at −70 mV, and also to disconnect the reference electrode from the amplifier. The other set was used to disconnect the electrodes from the pulse generator until the time of NEP/sham exposure. The sequence and timing of both sets of relays were computer-controlled. Using this procedure, we observed that a 5-ns pulse induced an instantaneous inward current that decayed exponentially over the course of several minutes, that a second pulse induced a similar response, and that the current was carried, at least in part, by Na+. This approach for characterizing ion conductance changes in an excitable cell in response to NEPs will yield information essential for assessing the potential use of NEP stimulation for therapeutic applications.
| non-battery |
Utilities have greatly increased the use of time-of-use (TOU) rate structures for residential customers to more closely match the cost of delivered electricity as well as demand tariffs to incentivize a temporal shift in residential energy use. However current research tends to focus on a particular climate or location. This study analyzes four residences across four different climate zones in Arizona and explores the value of adding battery storage to a net-zero energy (NZE) photovoltaic (PV) system. Using the National Renewable Energy Lab's Building Optimization (BEopt) and System Advisor Model (SAM) tools, this study performs parametric analysis by varying battery size to determine a capacity that produces a maximum net present value (NPV). A sensitivity analysis on three possible future battery price trends is also performed. This study finds the NZE PV systems are only able to mitigate 37–44% of the peak electricity purchases and 4–12% of demand charges due to mismatch between solar potential and on-peak hours. Adding large batteries, 1.5–1.6 times larger than required to meet the annual peak energy purchase requirements, provides a maximum NPV for PV-battery systems at locations with favorable utility rates. We conclude that the best economics are achieved, at both current and expected future battery prices, when batteries are sized to never require replacement during the PV system lifetime. | battery |
With the advancement of smart home and grid, a more connected and efficient operation of the grid is achievable. Involving buildings as the largest consumer of electricity in such a smart operation is a critical step in achieving an interactive grid system. In this paper, a building energy management system is introduced considering electricity price and people behavior, controlling major consumers of electricity in a single family residential building. An air conditioner, water heater, electric vehicle, and battery storages are controlled in a photovoltaic (PV) equipped building. A model predictive control is designed to minimize the operation cost considering system model, electricity price and people behavior patterns in each device control. Centralized and stand-alone configuration of MPC for building energy management is formulated and were put in contrast for time of use pricing (TOU), hourly pricing and five minutes pricing. Simulation results show that in real time five minutes pricing these methods can achieve 20%–30% cost savings in different appliances, and 42% savings in overall electricity cost adding battery optimal control compared to traditional rule based control. Cost savings and peak shaving results demonstrate the capabilities of introduced price and behavior based control. | non-battery |
In this study, carbon additives such as activated carbon (AC) and carbon black (CB) are introduced to the negative electrode to improve its electrochemical performance, the negative electrode sheets are prepared by simulating the negative plate manufacturing process of lead-acid battery, the types and contents of carbon additives in the negative electrode sheets are investigated in detail for the application of lead-carbon battery. The electrochemical performance of negative electrode sheets are measured by chronopotentiometry, galvanostatic charge-discharge and electrochemical impedance spectroscopy, the crystal structure and morphology are characterized by X-ray diffraction and scanning electron microscopy, respectively. The experimental results indicate that the appropriate addition of AC or CB can enhance the discharge capacity and prolong the cycle life of negative electrode sheets under high-rate partial-state-of-charge conditions, AC additive exerts more obvious effect than CB additive, the optimum contents for the best electrochemical performance of the negative electrode sheets are determined as 0.5wt% for both AC and CB. The reaction mechanism of the electrochemical process is also discussed in this paper, the appropriate addition of AC or CB in negative electrode can promote the conversion of PbSO4 to Pb, suppress the sulfation of negative electrode sheets and reduce the electrochemical reaction resistance. | battery |
Carbon black supercapacitors that employ thin (∼1μm) electrodes were produced by coating and inkjet printing on a conventional current collector or directly on a separator membrane. The simplicity and diversity of ultrathin electrode fabrication were facilitated by the physical form of carbon black, which can be described as a fine particle of around 100nm in size. It was established that the performance of carbon black in thin supercapacitor electrodes may be compared with carbon nanotube and graphene materials in those instances where fast frequency response is desired from the supercapacitor. At the same time, the fast response supercapacitors that employ nanotubes and graphenes have presently involved more elaborate fabrication routes. RC time constant of 354μs and phase angle of −75° at 120Hz is demonstrated for carbon black supercapacitors that employ SC3 carbon black of 1800m2 g−1 surface area. | battery |
Depression affects 7% of the elderly population, and it often remains misdiagnosed or untreated. Peripheral biomarkers might aid clinicians by allowing more accurate and well-timed recognition of the disease. We sought to determine if plasma protein levels predict the severity of depressive symptomatology or distinguish patients from healthy individuals. The severity of depressive symptoms and global cognitive functioning were assessed by the Geriatric Depression Scale (GDS) and Mini-Mental State Examination (MMSE) in 152 elderly subjects, 76 of which with major depressive disorder (MDD). Plasma levels of 24 proteins were measured by multiplexing and analyzed as continuous predictors or dichotomized using the median value. The association between individual plasma proteins and MDD risk or depressive symptoms severity was investigated using multiple logistic and linear regressions including relevant covariates. Sensitivity analyses were performed excluding cognitively impaired individuals or non-acute patients with MDD. After adjusting for possible confounders and false discovery rate (FDR) correction, we found lower Fetuin-A levels in MDD patients vs. controls (pFDR = 1.95 × 10–6). This result was confirmed by the sensitivity and dichotomized analyses. Lower prolactin (PRL) levels predicted more severe depressive symptoms in acute MDD patients (pFDR = 0.024). Fetuin-A is a promising biomarker of MDD in the elderly as this protein was negatively associated with the disorder in our sample, regardless of the global cognitive functioning. Lower PRL levels may be a peripheral signature of impaired neuroprotective processes and serotoninergic neurotransmission in more severely depressed patients. | non-battery |
Co–Te–O catalytic films, obtain by vacuum co-evaporation of Co and TeO2 are investigated as electrocatalysts for oxygen reactions in alkaline media. Bifunctional gas-diffusion oxygen electrodes (gde) are prepared by direct deposition of catalyst films on gas-diffusion membranes (gdm) consisting of hydrophobized carbon blacks or hydrophobized “Ebonex” (suboxides of titanium dioxide). Thus obtained electrodes with different atomic ratio R Co/Te of the catalyst, treated at different temperatures were electrochemically tested by means of cyclic voltammetry and steady-state voltammetry. It is shown that the electrodes exhibit high catalytic activity toward oxygen evolution and reduction reaction despite very low catalyst loading of about 0.05–0.5mgcm−2. | battery |
Supercapacitors have been widely viewed as one promising candidate of next-generation energy storage devices. To configure a supercapacitor with high-charge storage for practical applications, it is one of urgent issues to take up effective/universal strategies to well tailor electrode materials for desired properties and functions. As one of representative materials with intrinsic pseudocapacitive behaviors, MnO2 is attractive because of high theoretical capacitance value and large potential window. Nevertheless, a wide gap between the practical and theoretical capacitance value greatly hinders its further applications and remains a major challenge. Herein, we systematically reviewed recent advances on activating intrinsic capacitive properties of MnO2 to shorten this distance, which was classified into five branches including conductive species coupling, single/few-layers constructing, heterojunction configuring, defects engineering and metal doping. In addition, an outlook on the practical applications of MnO2 and involved potential challenges in energy storage field was discussed and highlighted. It is believed that this article can function as a momentum calling for more endeavors into development of advanced electrode materials with fasinating capacitive performance. | battery |
Graphene is a promising electrode material for energy storage applications. The most successful method for preparing graphene from graphite involves the oxidation of graphite to graphene oxide (GO) and reduction back to graphene. Even though different chemical and thermal methods have been developed to reduce GO to graphene, the use of less toxic materials to generate graphene still remains a challenge. In this study we developed a facile one-pot synthesis of deoxygenated graphene (hGO) via alkaline hydrothermal process, which exhibits similar properties to the graphene obtained via hydrazine reduction (i.e. the same degree of deoxygenation found in hydrazine reduced GO). Moreover, the hGO formed freestanding, binder-free paper electrodes for supercapacitors. Coin cell type (CR2032) symmetric supercapacitors were assembled using the hGO electrodes. Electrochemical characterization of hGO was carried out using lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and ethylmethylimidazolium bis-(trifluoromethanesulfonyl)imide (EMITFSI) electrolytes. The results for the hGO electrodes were compared with the hydrazine reduced GO (rGO) electrode. The hGO electrode exhibits a energy density of 20 W h kg−1 and 50 W h kg−1 in LiTFSI and EMITFSI respectively, while delivering a maximum power density of 11 kW kg−1 and 14.7 kW kg−1 in LiTFSI and EMITFSI, respectively. | battery |
A novel rechargeable hybrid Na-seawater flow battery, using natural seawater as an abundant source of active materials, have been developed recently. In this kind of metal-air battery, electrochemical oxygen evolution and reduction are the two key processes taking place during charging and discharging, respectively. In general, powder form of electrocatalysts are attached to the current collectors by using inactive and insulating polymer binders, which inevitably impede the overall performance, and increase the manufacturing costs of the battery. Therefore, a simple way to construct the 3D current collector combined with efficient electrocatalytic activities remains a big challenge. In this work, a 3D macroporous carbon sponge is prepared by the direct carbonization of commercially available polymer “Magic Eraser”. The obtained carbon sponge has interconnected macroporous open 3D scaffold structure and exhibits good flexibility and tailorability. The 3D macroporous carbon sponge shows good bifunctional electrocatalytic activities toward oxygen evolution and reduction reactions in seawater. The fabricated hybrid Na-seawater flow battery using 3D macroporous carbon sponge as cathode current collector displays small charge-discharge voltage gap with high voltage efficiency, excellent rechargeability, and long-term cycling stability. | battery |
Pt-based bimetallic alloys have attracted intensive interests as highly efficient and stable heterogeneous catalysts for fuel cell applications, and searching flexible free-standing nanomembranes has been on the research focus because of their promising applications in catalysis, nanoelectronics, batteries, and sensing. Herein, a flexible free-standing paper composed of FePt alloy nanoparticles on nitrogen-doped paper (FePt–NG paper) has been developed as integrated electrode towards electrocatalytic oxidation of formic acid. It is found that, N doping is beneficial for the well dispersion of FePt nanoparticles on NG paper. The synergistic effect between Fe and Pt, as well as N doping effect simultaneously assures the improved catalytic activity of FePt–NG paper, making it the promising flexible electrode for application in fuel cell system. Moreover, the synthesis strategy could be used for the construction of other free-standing electrode towards catalysis, sensing, and battery applications. | battery |
Transcutaneous electric acupoint stimulation (TEAS) avoids the use of needles, and instead delivers a mild electric current at traditional acupoints. This technique has been used for treating heroin addiction, but has not been systematically tested for other drugs of abuse. This study aims to investigate the effects of TEAS on drug addiction. | non-battery |
In this work, we perform a comprehensive study of five phenomena of LiNi1-2xCoxMnxO2 (NCM) (x = 0–1/3) cathodes at the end of charge (phase reaction, crack propagation, Li-Ni exchange, phase transition, and oxygen evolution), using first-principle calculations within the DFT + U framework. Based on our results, we have located the obstacles toward unity efficiency and revealed that the degradation strongly depends on the Ni concentration and the depth of charge. The threshold capacities for degradation of LiyNi1-2xCoxMnxO2 are 130–140 mA·hg−1 (y < 0.5) for 1/4 ≤ x = 1/3 (33.33–50% of Ni), and 200–210 mA·hg−1 (y < 0.25) for 0 ≤ x = 1/4 (50–100% of Ni), respectively. For 1/4 ≤ x = 1/3, our results show that the origin of the degradation is the oxidation of O2−, which is the result of the pining of O-p and Ni-d bands at the valence band edge. For 0 ≤ x = 1/4, lattice distortion and Li-Ni exchange are the mechanisms responsible for the degradation of the cathode material, leading to severe structural instabilities in the Ni-rich region (x = 0.1). Our findings will help to rationally design NCM cathode materials with high-energy density, also providing possible solution mechanisms to the degradation factors, such as doping, coating or novel nanostructures, like core-shell or concentration gradient cathodes. | battery |
A novel conducting polymer of polynaphthidine, poly(NAP), was synthesized electrochemically by direct anodic oxidation of naphthidine in aqueous media. The yield of the electropolymerization reaction depends on the temperature and pH of the solution. It was possible to differentiate two working regions: I (for pH<0.5 and all temperatures) where the film yield tends to zero and II (for approximately 2.0<pH<2.8 and temperatures >15°C) where the film production is maximum. Therefore, the naphthidine electrooxidation mechanism was studied under experimental conditions of region I by cyclic (CV) and square wave voltammetries (SWV) as well as by controlled potential electrolysis. The experimental conditions of region II were chosen to obtain the poly(NAP). The electrochemical response of the film was investigated in pH 1 HClO4 +0.1M NaClO4 electrolyte solution by CV and SWV. A plot of I p,n/f vs. f from SW voltammograms showed the so-called “quasi-reversible maximum”. Formal potential, formal rate constant and anodic transfer coefficient for the surface redox process were also evaluated from the SWV. The poly(NAP) is insoluble in common organic solvents and shows electrochromic behaviour. Its probable structure was determined by FTIR spectroscopy. | battery |
This work reports the results of a systematic study on the effect of Co as substituent for Ni on several physical and electrochemical properties of LaNi4.7−x Sn0.3Co x metal hydride alloys, where 0≤x≤0.7. These included the unit cell lattice parameters measured using X-ray diffraction (XRD) and the electronic properties obtained using X-ray absorption spectroscopy (XAS). In general, the presence of cobalt in the alloys causes a decrease on the hydrogen equilibrium pressure and on the rate of capacity decay, and an increase in the cycle life and on the alloy activation time. A negligible effect of Co is observed in the maximum charge storage capacity and on the catalytic activity with respect to the hydrogen oxidation reaction (HOR). | battery |
Optimal investment in battery energy storage systems, taking into account degradation, sizing and control, is crucial for the deployment of battery storage, of which providing frequency control is one of the major applications. In this paper, we present a holistic, data-driven framework to determine the optimal investment, size and controller of a battery storage system providing frequency control. We optimised the controller towards minimum degradation and electricity costs over its lifetime, while ensuring the delivery of frequency control services compliant with regulatory requirements. We adopted a detailed battery model, considering the dynamics and degradation when exposed to actual frequency data. Further, we used a stochastic optimisation objective while constraining the probability on unavailability to deliver the frequency control service. Through a thorough analysis, we were able to decrease the amount of data needed and thereby decrease the execution time while keeping the approximation error within limits. Using the proposed framework, we performed a techno-economic analysis of a battery providing 1 MW capacity in the German primary frequency control market. Results showed that a battery rated at 1.6 MW, 1.6 MWh has the highest net present value, yet this configuration is only profitable if costs are low enough or in case future frequency control prices do not decline too much. It transpires that calendar ageing drives battery degradation, whereas cycle ageing has less impact. | battery |
A facile solvothermal way to immobilize nanocrystalline LiMn2O4 on the surface of graphene nanosheets is developed to improve the functionality of lithium manganate as lithium intercalation electrode. A solvothermal treatment for the colloidal mixture of graphene oxide (GO) nanosheets and LiMn2O4 nanocrystals gives rise not only to the reduction of GO to reduced graphene oxide (RGO) but also to the immobilization of lithium manganate nanoparticles on the surface of RGO nanosheets. According to powder X-ray diffraction and electron microscopic analyses, the crystal structure and morphology of spinel lithium manganate remain intact upon the composite formation with the RGO nanosheets. The application of larger aldehyde molecule as a reductant leads to the increase of crystallinity and the lowering of Mn oxidation state for the pristine LiMn2O4 and its nanocomposite with the RGO nanosheets. The present LiMn2O4–RGO nanocomposites display promising cathode performances for lithium rechargeable batteries, which are much superior to those of the pristine LiMn2O4 nanocrystals. The observed enhancement of electrode performance upon the composite formation with the RGO nanosheets is attributable both to the improvement of the surface ion transport of nanocrystalline lithium manganate and to the increase of electrical conductivity. The present experimental findings demonstrate that the solvothermal treatment with RGO nanosheets provides an effective way of improving the electrochemical activity of nanocrystalline lithium metal oxides. | battery |
High lithium ion conducting 70Li2S·(30− x)P2S5·xP2S3 (mol%) glasses and glass–ceramics were prepared by the mechanical milling method. Glasses were obtained in the composition range of 0≦ x ≦10. The substitution of P2S3 for P2S5 promoted the formation of the P2S6 4− units in the glasses. The conductivity of the glass increased with an increase in P2S3 contents up to 5mol% and the glass with 5mol% of P2S3 showed the conductivity of 1×10−4 Scm−1 at room temperature. In the case of glass–ceramics, the conductivity increased with an increase in P2S3 contents up to 1mol%, and the superionic conducting Li7P3S11 crystal was precipitated in the glass–ceramic. The glass–ceramic with 1mol% of P2S3 showed the highest conductivity of 3.9×10−3 Scm−1 at room temperature. | battery |
In this paper, we report a modeling methodology on the transient behaviors of a lithium-ion battery (LIB) during dynamic cycling. To account for the short time effects of current pulses and rest periods, the nonfaradaic component of the current density transferred through the separator between the positive and negative electrodes is included based on the lumped double-layer capacitance. Two-dimensional modeling is performed to predict the transient behaviors of an LIB cell during dynamic cycling. To validate the modeling approach presented in this work, modeling results for the variations in cell voltage and two-dimensional temperature distribution of the LIB cell as a function of time are compared with the experimental data for constant-current discharge and charge cycles and the Heavy Duty Urban Dynamometer Driving Schedule cycles. The transient behaviors obtained from the modeling agree well with the experimental measurements. | battery |
The interfacial capacitance of large area, single layer graphene was directly measured with electrolyte accessing both sides of the graphene sheet. PMMA and photoresist patterns were used as supports to suspend the CVD grown graphene in electrolyte during electrochemical testing. Both one and two sides of single layer graphene films were measured and compared. The results show that the area normalized charge that can be stored simultaneously on both sides is significantly lower than could be stored on just one side of single layer graphene, consistent with charge storage having a quantum capacitance component. These measurements are also consistent with the specific capacitance of graphene materials as previously measured in supercapacitor cells and provide a basis for the further understanding and development of graphene based materials for electrical energy storage.
| battery |
Individual differences in vulnerability to neurobehavioral performance impairment during sleep deprivation are considerable and represent a neurobiological trait. Genetic polymorphisms reported to be predictors have suggested the involvement of the homeostatic and circadian processes of sleep regulation in determining this trait. We applied mathematical and statistical modeling of these two processes to psychomotor vigilance performance and sleep physiological data from a laboratory study of repeated exposure to 36h of total sleep deprivation in 9 healthy young adults. This served to quantify the respective contributions of individual differences in the two processes to the magnitudes of participants’ individual vulnerabilities to sleep deprivation. For the homeostatic process, the standard deviation for individual differences was found to be about 60% as expressed relative to its group-average contribution to neurobehavioral performance impairment. The same was found for the circadian process. Across the span of the total sleep deprivation period, the group-average effect of the homeostatic process was twice as big as that of the circadian process. In absolute terms, therefore, the impact of the individual differences in the homeostatic process was twice as large as the impact of the individual differences in the circadian process in this study. These modeling results indicated that individualized applications of mathematical models predicting performance on the basis of a homeostatic and a circadian process should account for individual differences in both processes. | non-battery |
Considering inherent large structural deterioration of conversion-type anode materials during repeated sodiation/desodiation process, the ingenious integration of both nanostructure engineering and chemical hybridization is highly desirable and challenging. Here, ultrafine CoS nanoparticles embedded in porous carbon nanorods (denoted as 7-CoS/C) were facilely fabricated via simultaneous in-situ carbonization and sulfidation of Co-metal organic frameworks (Co-MOF) and have been applied as anode materials for sodium-ion batteries (SIBs). Benefiting from the advantageous embedding architecture between the nanoparticles and porous nanorods, the 7-CoS/C delivers long-term cycling stability (542mAhg−1 after 2000 cycles with a capacity retention of 91.4% at 1Ag−1) and excellent rate performance (discharge capacities of 510mAhg−1 at 5Ag−1 and 356mAhg−1 even at 40Ag−1), which is proved to be characterized of partial pseudocapacitive behaviors during the sodiation/desodiation process. In addition, Na3V2(PO4)3/7-CoS/C full cell with excessive amount of Na3V2(PO4)3 has been assembled and exhibits a capacity of 352mAhg−1 at 0.5Ag−1. This meaningful approach can be extended to build embedded porous structure of other hybrid composites for next-generation energy-storage technology. | battery |
To address the corrosion and dendrite issues of lithium metal anodes, a protective layer was ex-situ constructed by P4S10 modification. It was determined by X-ray photoelectron spectroscopy and Raman spectra that the main constituents of the protective layer were P4S10, Li3PS4 and other Li x P y S z type derivatives. The protective layer was proved to be effective to stabilize the interphase of lithium metal. With the modified Li anodes, symmetric cells could deliver stable Li plating/stripping for 16000 h; Li–S batteries exhibited a specific capacity of 520 mA h g−1 after 200 cycles at 1000 mA g−1 with average Coulombic efficiency of 97.9%. Therefore, introducing Li x P y S z based layer to protect Li anode provides a new strategy for the improvement of Li metal batteries. | battery |
MnFe2O4/reduced graphene oxide nanocomposite (MnFe2O4/rGO) has been synthesized via a green reduction-coprecipitation method for the first time, which involved in situ reduction of GO in presence of Fe2+ and the ensuing coprecipitation of Fe3+ and Mn2+ onto the surface of rGO. The resultant MnFe2O4/rGO was then employed as the precursor to fabricate LiMn1/3Fe2/3PO4/reduced graphene oxide/carbon composite (LiMn1/3Fe2/3PO4/rGO/C) cathode material for Li-ion batteries. The composite consists of homogeneous Mn-Fe distributed LiMn1/3Fe2/3PO4 with its primary particles (∼200nm) covered and connected by both pyrolytic carbon and rGO sheets, which could prevent the aggregation of the particles as well as construct an interconnected conductive network for rapid transmission of electrons during charging and discharging process. The fabricated LiMn1/3Fe2/3PO4/rGO/C can deliver a discharge capacity of 94.8mAhg−1 even at the high rate of 20C, and shows a capacity decay rate of only 6.25% after 900 long-term charge-discharge cycles. Moreover, the proposed synthesis strategy can also be applied to prepare other graphene-decorated multi-component cathode/anode materials for the Li-ion batteries. | battery |
Understanding the degradation mechanism of Lithium-ion batteries (LIBs) is critical in developing high-performance LIBs, and the investigation of their electrical conductivity evolution during cycling can lead to a better understanding of the degradation mechanism of the cathode materials for Li-ion batteries (LIBs). Here, we studied the evolution of the electrical conductivity of LiNi0.8Co0.15Al0.05O2 (NCA) particles for LIB cathodes using scanning spreading resistance microscopy (SSRM). After 300 charge/discharge cycles, stepwise-increasing resistance distributions toward the centers of the secondary particles are observed. These distributions correspond to the degenerated granular structures of the secondary particles caused by the formation of microcracks. In addition, the correlation between the electrical conductivity and microstructure of the NCA cathode is established to explain the observed decay of the NCA discharge capacity. Our findings can provide an insight into the debatable degradation mechanism of LIB cathode materials such as NCA and NMC (LiNixMnyCozO2, x + y + z = 1). | battery |
Herein, a new nanocomposite was synthesized via in-situ growth of Fe3O4 nanoparticles on MXene Ti3C2 multilayer to improve the electrochemical performance of anodes by integrating the merits of transition metal oxide and Ti3C2, where further surface modification of Fe3O4@Ti3C2 nanocomposites by carbon coating was introduced here. The nanocomposites exhibited excellent electrochemical performance in Li-ion storage when used as the anode materials, which benefited from the combination of the high capacity of magnetite and favorable electrical conductivity of Ti3C2. The optimized Fe3O4@Ti3C2-2.5 (a mass ratio of 1.1) showed a high reversible capacity of 342.9 mAh·g−1 at 1C, which exceeded the theoretical capacity of bare Ti3C2 monolayer (320 mAh·g−1), and an impressive rate reversibility. TEM presented that the carbon layers were homogeneously coated on the surface of nanocomposites with a thickness of approximately 1 nm. The electrochemical measurement showed that C-coated Fe3O4@Ti3C2-2.5 presented enhanced cycling performance (382.9 mAh·g−1 at 1C and 236.7 mAh·g−1 at 5C) and cycling stability. This work presents a promising route for preparation of transition metal oxides@MXene nanocomposites as well as further surface modification for advanced Li-ion storage. | battery |
Background To determine whether increasing claudication severity is associated with impaired balance and physical functional ability. Methods A prospective observational study in claudicants was performed. Disease severity was determined according to Rutherford’s criteria. Patient’s balance was assessed objectively using computerized dynamic posturography (CDP—Sensory Organization Test [SOT]; NeuroCom). “Bedside” assessment of balance was performed using the Timed Up and Go (TUG) test (dynamic balance) and the Full Tandem Stance test (static balance). Physical function was assessed using the Summary Physical Performance Battery (SPPB) score. Results 185 claudicants were assessed (median age of 69 [IQR 63–74] years; 137 [74.1%] men). Fourteen claudicants were classified as Rutherford grade 0, 26 as grade I, 76 as grade II, and 69 as grade III. All Rutherford groups were comparable for age, gender, BMI, and comorbidities. Increasing Rutherford grade was associated with a significant deterioration in objective balance as determined by a failed SOT test: 3 (21.4%) in grade 0; 9 (34.6%) in grade I; 39 (52.7%) in grade II; and 41 (59.4%) in grade III (chi-squared 9.693, df 3, P = 0.021). A significant difference was also found with dynamic balance (TUG test), but not static balance (full tandem stance). Increasing claudication severity was also associated with significantly worse physical function: SPPB score. Conclusions Specific objective tests demonstrate impaired balance and physical function are common in claudicants and become more frequent with increasing severity of claudication. Simple “bedside” measures may be sufficiently sensitive to detect this. | non-battery |
Rejects from selective collection are municipal solid waste (MSW) not used for recycling and are, therefore, destined for the landfill in Brazil. Knowledge of the composition and generation of this waste is important for strategically planning public policies that minimize its generation and its negative environmental impacts. However, this portion of MSW is not very well known. Therefore, the aim of this study was to analyze the rejects from the sorting process of the selective waste collection in the municipality of Blumenau, in the State of Santa Catarina, southern Brazil. The studied rejects came from the largest cooperative in the city, and its composition was sorted into 17 categories of 101 samples over the course of one year, with a total of 3893 kg of analyzed rejects. The waste collected by the selective collection of the municipality was evaluated monthly to determine which part of this quantity became rejects and to determine the composition and seasonality of these rejects. The study found that 30.5% of the waste sorted by the cooperative was rejected. Among these rejects, the presence of materials that could be marketed by the cooperative was verified. Hazardous and/or legally prohibited waste were also identified, as were organics, construction and demolition waste, health care waste, electronics, textiles, footwear, batteries, and bulbs. Seasonal analysis indicated a concerning constant generation of health care waste. Aside from that, there was an increase in the generation of waste from electrical and electronic equipment (EEE) during the Christmas period, when a large part of the population discards their EEE. This information is important for the enforcement of the MSW management structure as well as for educational campaigns aimed at the correct separation of waste that should be sent for selective collection. | non-battery |
The K2FeO4/TiB2 battery has a significant advantage of battery capacity due to their multi-electron discharge reaction both of the cathode K2FeO4 (3e−) and the anode TiB2 (6e−). However, the more positive reduction potential of TiB2 anode results in a lower discharge voltage plateau of K2FeO4/TiB2 battery, compared with the K2FeO4/Zn battery. The simple modification of Fe(VI) cathode with CuO additive was used to improve the cathode reduction kinetics and decrease the polarization potential in the discharge process. Another electrocatalysis media RuO2 with excellent electric conductivity is used as additive in K2FeO4 cathode to demonstrate which effect is more important for the discharge voltage plateau, electrocatalysis or electron conductivity of additives. The results show that the 5% CuO additive modified K2FeO4/TiB2 battery exhibits an enhanced discharge voltage plateau (1.5V) and a higher cathode specific capacity (327mAh/g). The advanced discharge voltage plateau can be due to the electrocatalysis of additives on the electrochemical reduction kinetics of Fe(VI) cathode in the whole discharge process, rather than the good electronic conductivity of additives. | battery |
The implementation of mobile health (mHealth) projects in low- and middle-income countries raises high and well-documented expectations among development agencies, policymakers and researchers. By contrast, the expectations of direct and indirect mHealth users are not often examined. In preparation for a proposed intervention in the Nouna Health District, in rural Burkina Faso, this study investigates the expected benefits, challenges and limitations associated with mHealth, approaching these expectations as a form of situated knowledge, inseparable from local conditions, practices and experiences. | non-battery |
In this paper, a novel method to generate electrical energy by converting available mechanical energy from pressure fluctuations of the cerebrospinal fluid within lateral ventricles of the brain is presented. The generated electrical power can be supplied to the neural implants and either eliminate their battery need or extend the battery lifespan. A diaphragm type harvester comprised of piezoelectric material is utilized to convert the pressure fluctuations to electrical energy. The pressure fluctuations cause the diaphragm to bend, and the strained piezoelectric materials generate electricity. In the framework of this study, an energy harvesting structure having a diameter of 2.5 mm was designed and fabricated using microfabrication techniques. A 1:1 model of lateral ventricles was 3D–printed from raw MRI images to characterize the harvester. Experimental results show that a maximum power of 0.62 nW can be generated from the harvester under similar physical conditions in lateral ventricles which corresponds to energy density of 12.6 nW/cm2. Considering the available area within the lateral ventricles and the size of harvesters that can be built using microfabrication techniques it is possible to amplify to power up to 26 nW. As such, the idea of generating electrical energy by making use of pressure fluctuations within brain is demonstrated in this work via the 3D–printed model system.
| non-battery |
This paper presents a life-cycle analysis for a new concept in solar thermal power generation. BRRIMS denotes Brayton-cycle, re-heated, recuperated, integrated, modular and storage-equipped. This concept envisages collection temperatures of around 250 °C, thermal storage in pebble beds, thermal-electric conversion in a piston–cylinder engine and air as the heat transfer fluid and working gas of the engine. The analysis applies to the manufacturing phase of the overall power plant and separately to the pebble bed thermal storage component. Three sustainability metrics are included – life-cycle greenhouse gas emissions, cumulative energy demand and energy payback time. On these metrics, the BRRIMS concept has broadly similar results to a conventional parabolic trough plant with molten salt thermal storage. | battery |
It has been shown that songbird migrants can use several compass cues for orientation (e.g. sun position at sunset and possibly sunrise and related polarised light cues, stars and the geomagnetic field); therefore, the obtained information is redundant. This suggests that compasses of migratory birds must have certain hierarchical relationships and be calibrated. Currently, it is not known how avian compass calibration is accomplished. We report the results of our experiments with Garden Warblers Sylvia borin, long-distance songbird migrants. We tested the birds in two experimental conditions: in a local magnetic field with access to a starry sky (Control group) and in a vertical magnetic field that does not provide magnetic compass information with access to stars (Clear sky experimental group) or without it (Overcast experimental group), and analysed locomotor activity and orientation in all three groups. For the Garden Warblers from the control and experimental groups, we revealed two periods of activity separated by a quiescent period: twilight and nocturnal periods. The average direction for both periods of activity showed no significant difference in the control group. Birds from the experimental group were disoriented in both periods. Birds from the clear sky and overcast groups were also disoriented. These data suggest that long-distance songbird migrants, particularly the Garden Warbler, need information from the geomagnetic field, but not from the stars, at sunset and during twilight in order to choose the correct migratory direction. The nocturnal period of migratory activity probably represents actual migratory flight, while the nature of the twilight period remains unknown. The results of the present work and data from prior cue-conflict experiments on other species suggest that the twilight period may correspond to compass calibration activity. | non-battery |
Whole plant foods can be fermentable by SCFA-producing bacteria and positively influence host adipose tissue development and obesity related-metabolic disorders, conferring a prebiotic role. Considering the juçara berry composition, rich in fiber and polyphenols, we hypothesized the probable prebiotic role of juçara in individuals with obesity. | non-battery |
In this article an economic and environmental study is carried out on PV solar energy installations connected to the Spanish electrical grid system. The study has been performed on installations situated in the city of Zaragoza (with an irradiation value approximately equal to the average value for Spain). Initially, an economical study is performed, proposing different scenarios where different values of interest rate and energy tariffs are considered. The following parameters are used to determine the profitability of a PV installation: the Net Present Value and the Pay-Back Period. Furthermore, the environmental benefits of PV systems connected to the grid have been evaluated. This has been accomplished using the Life Cycle Analysis theory of the systems, calculating the recuperation time of the invested energy, the contamination or emissions avoided and the externality costs. Finally the possible effects of the application of the Kyoto Protocol have been studied. | battery |
Battery inconsistency are exacerbated by the resistance of inter-cell connecting plate (RICP) and the input impedance of battery voltage monitoring system (IIBVMS), both of which cannot be eliminated in a battery pack. Experiments show that the inconsistency distribution and SOC deviation in a battery pack is restricted by RICP and IIBVMS. In this paper, a “parallel-series” battery pack model is proposed and validated. The effects of RICP and IIBVMS on SOC deviation are analyzed. Results indicate that RICP causes unevenly current flowing through each in-parallel battery cell, and so the battery cell directly connected to the battery module posts presents the lowest SOC. In order to restrict SOC deviation to an acceptable level, the equivalent relation of the battery inconsistency caused by RICP to the inherent inconsistency is discussed. The reasonable matching RICP is then presented. IIBVMS causes different current leakage in each voltage sampling line. The closer the battery module connects to the positive terminal of a battery pack, the higher leakage current is. The different leakage current in each voltage sampling line exacerbates battery inconsistency and causes different initial SOC for each battery module. The relationship among the leakage current, the input impedance and the number of in-series battery modules are discussed. And an improved schematic diagram of battery module voltage sampling is further presented to lower the leakage current and to solve the sampling time delay caused by the multi-switch. | battery |
We report (electro-)chemically stable, high temperature resistant and fast wetting Li-ion battery separators produced through a phase inversion process using novel polyetherimides (PEI) based on bisphenol-aceton diphthalic anhydride (BPADA) and para-phenylenediamine (pPD). In contrast to previous studies using PEI based on BPADA and meta-phenylenediamine (mPD), the separators reported herein show limited swelling in electrolytes and do not require fillers to render sufficient mechanical strength and ionic conductivity. In this work, the produced 15–25 μm thick PEI-pPD separators show excellent electrolyte compatibility, proven by low degrees of swelling in electrolyte solvents, low contact angles, fast electrolyte wicking and high electrolyte uptake. The separators cover a tunable range of morphologies and properties, leading to a wide range of ionic conductivities as studied by Electrochemical Impedance Spectroscopy (EIS). Dynamic Mechanical Analysis (DMA) demonstrated dimensional stability up to 220 °C. Finally, single layer graphite/lithium nickel manganese cobalt oxide (NMC) pouch cells were assembled using this novel PEI-pPD separator, showing an excellent capacity retention of 89.3% after 1000 1C/2C cycles, with a mean Coulombic efficiency of 99.77% and limited resistance build-up. We conclude that PEI-pPD is a promising new material candidate for high performance separators. | battery |
The development of new materials is required to improve the energy density of Li-ion batteries. A new graphite type with optimised physical–chemical characteristics has been studied and developed to improve negative electrode performance. Lithium ion charge and discharge acceptance have been improved by the enhanced intrinsic properties of the material. The new material has higher efficiency electrode porosity/tortuosity, and increases electrical conductivity. This allows better charge performance at low temperatures and discharge performance at high rates. Combined with an optimised electrolyte composition, it also gives low and reproducible fading, good discharge performance in very low temperature conditions, and long term storage at high temperatures. Due to this and other design modifications that will be discussed, a 22% improvement in energy density is obtained in the new generation of Saft Li-ion medium prismatic cells (MP). | battery |
TiO2 mesoporous single crystals (MSCs) with diverse constructions in a controllable fashion are successfully fabricated by a new template-free method for the first time, using oxalic acid (OA) as the pore-forming agent and morphological controller. Unlike the seeding-template based growth mechanism, the TiO2 MSCs in the present work may involve a process of oriented aggregation and crystallographic fusion of primary nanocrystals. The structural control of TiO2 MSCs can be easily realized by tailoring growth conditions, such as Ti-source concentration and OA dosages. Moreover, the TiO2 MSCs shows substantial improvement in lithium specific capacity from 0.2C to 10C in comparison to the reference TiO2 nanoparticle. The high-rate performance was further improved by fabricating MSCs/graphene oxide nanocomposites, and specific capacity of the composite at the rate of 20C is as high as 90mAhg−1. This new template-free strategy may open up new and exciting opportunities for the preparation of other MSCs, and makes important applicatory significance for the structure design of high-rate lithium ion battery anodes. | battery |
Carbon–carbon (C–C) composite has been investigated as an anode for lithium-ion battery systems. The composite electrode delivers high reversible capacity and very low irreversible capacity loss. The test results of lithium-ion cells made with the C–C composite anode show many advantages, such as excellent performance and enhanced safety. The performance improvement is achieved because of strong mechanical integrity (cycle life) and absence of binder (shelf life) in C–C composite. The enhancement in safety comes from high thermal conductivity, fire retardant characteristics and an acceptable ability to overcharge and overdischarge. | battery |
This paper outlines new work in cross-cultural psychology largely drawn from Nisbett, Choi, and Smith (Cognition, 65, 15–32, 1997); Nisbett, Peng, Choi, & Norenzayan, Psychological Review, 108(2), 291–310, 2001; Nisbett, The Geography of Thought: How Asians and Westerners Think Differently...and Why. New York: Free Press 2003), Ji, Zhang and Nisbett (Journal of Personality and Social Psychology, 87(1), 57–65, 2004), Norenzayan (2000) and Peng (Naive Dialecticism and its Effects on Reasoning and Judgement about Contradiction. University of Michigan, Ann Arbor, Michigan 1997) Peng and Nisbett (Cross-Cultural Similarities and Differences in the Understanding of Physical Causality. Paper presented at the Science and Culture: Proceedings of the Seventh Interdisciplinary Conference on Science and Culture, Frankfort, K. Y. 1996), and Peng, Ames, & Knowles (Culture and Human Inference: Perspectives from three traditions. In: D. Matsumoto (Ed.), Handbook of Cross-Cultural Psychology (pp. 1–2). Oxford: Oxford University Press 2000). The paper argues that the findings on cultural influences on inference-making have implications for teaching and education generally, and specifically for the debate on conceptions and misconceptions of Asian students studying in western tertiary institutions around the world. The position defended is that, while there seems to be compelling empirical evidence for intercultural differences in thought patterns, these patterns are, for the most part, insignificant in everyday exchanges, though language and culture might subtlety modulate our inference-making at the margins. Linguistic determinism however is not defended. Nonetheless, the evidence provides food for thought, and it needs to inform the recent debates about international students studying overseas. | non-battery |
Managed artificial recharge (MAR) is a well-established practice for augmentation of depleted groundwater resources or for environmental benefit. At the St-André MAR site in the Belgian dune area, groundwater resources are optimised through re-use of highly treated wastewater by means of infiltration ponds. The very high quality of the infiltration water sets this system apart from other MAR systems. The low total dissolved solid (TDS) content in the infiltration water (less than 50 mg/L) compared to the dune aquifer (500 mg/L) triggers a number of reactions, increasing the TDS through soil-aquifer passage. Multi-component reactive transport modelling was applied to analyse the geochemical processes that occur. Carbonate dissolution is the main process increasing the TDS of the infiltration water. Oxic aquifer conditions prevail between the infiltration ponds and the extraction wells. This is driven by the high flow velocities, leaving no time to consume O2 between the ponds and extraction wells. Cation exchange is important when infiltration water is replaced by native dune water or when significant changes in infiltration-water quality occur. The seasonal variation of O2 and temperature in the infiltration water are the main drivers for seasonal changes in the concentration of all major ions. | non-battery |
Cerebrovascular disease is often associated with cognitive impairment. Owing to evolving definitional criteria, however, it has proved difficult to determine the frequency of vascular cognitive disorders in the general population. In this review, Ola Selnes and Harry Vinters review the current state of knowledge in the field of vascular cognitive impairment, emphasizing the neuropathologic and neurocognitive aspects. | non-battery |
A benzoquinone polymer is synthesized by the polymerisation of hydrobenzoquinone and formaldehyde, followed by oxidation process using a hydrogen peroxide to convert hydroquinone to quinone. As prepared materials are characterized with FTIR, 1H-13C CPMAS NMR, pyrolysis coupled with gas chromatography (GC) and mass spectrometer (MS), TGA-MS analysis, EDX, elemental analysis, XRD, SEM and TEM microscopies and BET nitrogen adsorption. The benzoquinone polymer shows an excellent electrochemical performance when used as a positive electrode material in Li-ion secondary batteries. Using an electrolyte consisting 1 M bis(trifluoromethane)-sulfonimide lithium salt dissolved in 1,3-dioxolane and dimethoxyethane in a vol. ratio 1:1 (1 M LiTFSI/DOL + DME = 1:1) a stable capacity close to 150 mAh/g can be obtained. Compared to other electroactive materials based on benzoquinones it has a supreme capacity stability and is prepared by a simple synthesis using easily accessible starting materials. Further improvements in the capacity value (up to the theoretical value of 406 mAh/g) can be foreseen by achieving a higher degree of oxidation and by modification of polymerization process to enhance the electronic and ionic conductivity. | battery |
Highly nonlinear structures and constituent materials and hazardous experiment situations have resulted in a pressing need for a numerical mechanical model for lithium-ion battery (LIB). However, such a model is still not well established. In this paper, an anisotropic homogeneous model describing the jellyroll and the battery shell is established and validated through compression, indentation, and bending tests at quasi-static loadings. In this model, state-of-charge (SOC) dependency of the LIB is further included through an analogy with the strain-rate effect. Moreover, with consideration of the inertia and strain-rate effects, the anisotropic homogeneous model is extended into the dynamic regime and proven capable of predicting the dynamic response of the LIB using the drop-weight test. The established model may help to predict extreme cases with high SOCs and crashing speeds with an over 135% improved accuracy compared to traditional models. The established coupled strain rate and SOC dependencies of the numerical mechanical model for the LIB aims to provide a solid step toward unraveling and quantifying the complicated problems for research on LIB mechanical integrity. | battery |
The present study reports on the direct synthesis of LiFePO4 nanoparticles and graphene nanosheets to form a composite cathode (LFP/GNs) in a one-step microwave-assisted polyol reaction. The polyol reaction induced by microwave irradiation for a few minutes produces nanocrystalline LFP and graphene nanosheets simultaneously from lithium, iron and phosphorus and carbon (5 wt% of graphite oxide) sources, respectively, used as starting precursors. Powder X-ray diffraction (XRD), electron microscopy, and atomic force microscopy (AFM) studies on microwave-reacted sample obtained using just graphite oxide confirms the formation of graphene nanosheets separately. Whereas, electron microscopy studies on the LFP/GNs composite reveals that olivine nanoparticles of average sizes ranging between 5 and 20 nm are well-dispersed on the graphene nanosheets. Electrochemical measurements reveal that the LiFePO4/GNs nanocomposite cathodes registered enhanced discharge capacities (79 and 108 mAh g−1 for the as-prepared and annealed composite cathodes, respectively) at 32 C rates with good capacity retention capabilities. The AC impedance measurements confirm that the enhanced cathode properties of the LFP/GNs nanocomposite are ascribed to the improved electronic conductivity of the graphene nanosheets and the nano-sized particles. The slightly better electrochemical properties of the annealed LFP/GNs are attributed to its higher crystallinity. | battery |
The purpose of this study was to compare the cognitive profiles of men and women with clinically defined schizotypal personality disorder (SPD). We examined the neuropsychological profile of SPD in 26 right-handed females and 31 right-handed males who met DSM-IV criteria for SPD, and matched comparison subjects. Cognitive performance was assessed on measures of abstraction, verbal and spatial intelligence, learning and memory, language, attention, and motor skills. Neuropsychological profiles were constructed by standardizing test scores based on the means and standard deviations of comparison groups matched for sex, age, handedness, ethnicity and parental SES. Overall, SPD subjects showed mild, general decrements in performance in most cognitive domains. However, unlike male SPD subjects, female SPDs did not show relative deficits in verbal learning and abstraction. The results suggest a less severe pattern of cognitive deficits in women with SPD compared to men, consistent with hypotheses of gender differences in cognitive function in schizophrenia. | non-battery |
Capacity fading of lithium ion batteries (LIBs) is a huge hurdle for their commercial utilization that may be reduced by the insertion of high quality anode material. Herein, we introduce high-graphitized graphene foam (GF) as anode material, which can be helpful for minimizing the loss of specific capacity during electrochemical reactions. GF shows excellent results when employed as anode in LIBs with high capacity values of 497mAhg−1 along with very low capacity fading (∼0.00578% at a current density of 200mAg−1). | battery |
Nowadays, renewable energy systems are taking place than the conventional energy systems. Especially, PV systems and wind energy conversion systems (WECS) are taking a big role in supplying world's energy necessity. Efficiency of such types of renewable energy systems is being tried to be improved by using different methods. Besides conventional methods, intelligent system designs are seem to be more useful to improve efficiency of renewable energy systems. However, artificial neural networks (ANN) have many usage areas in modeling, simulation and control of renewable energy systems. ANNs are easy to use and to implement renewable energy system designs. In this paper, artificial neural network applications of PV, WECS and hybrid renewable energy systems which consist of PV and WECS are presented. Usage of neural network structures in such types of systems have been motivated. | battery |
Gel polymer electrolyte (GPE) and composite gel polymer electrolyte (CGPE) have been widely employed to improve the safety and cycling performance of rechargeable lithium and lithium-ion batteries. In order to determine whether this approach is applicable to lithium/sulfur (Li/S) battery, we examine the effect of CGPE on the cycling and storage performances of Li/S cells by comparing a 50PEO-50SiO2 (wt.%) composite coated separator (C-separator) with a pristine separator (P-separator). Results show that the composite coating significantly enhances the wettability of liquid electrolyte on the separator and that resulting CGPE can tightly glue the separator and electrode together. In comparison with the P-separator, the C-separator offers Li/S cells similar capacity retention and rate capability; however it greatly affects the specific capacity of sulfur. The analysis on the impedance spectrum of a lithium polysulfide (PS) solution reveal that the reduction of sulfur specific capacity is due to the high viscosity of the CGPE and the strong adsorption of SiO2 filler to the PS species, which trap PS species in the separator and hence reduce the utilization of sulfur active material. Therefore, the benefits of the GPE and CGPE to the Li/S batteries can be taken only at the expense of sulfur specific capacity. | battery |
Wireless Sensor Networks (WSN) are large networks of tiny sensor nodes that are usually randomly distributed over a geographical region. The network topology may vary in time in an unpredictable manner due to many different causes. For example, in order to reduce power consumption, battery operated sensors undergo cycles of sleeping–active periods; additionally, sensors may be located in hostile environments increasing their likelihood of failure; furthermore, data might also be collected from a range of sources at different times. For this reason multi-hop routing algorithms used to route messages from a sensor node to a sink should be rapidly adaptable to the changing topology. Swarm intelligence has been proposed for this purpose, since it allows the emergence of a single global behavior from the interaction of many simple local agents. Swarm intelligent routing has been traditionally studied by resorting to simulation. The present paper aims to show that the recently proposed modeling technique, known as Markovian Agent Model (MAM), is suited for implementing swarm intelligent algorithms for large networks of interacting sensors. Various experimental results and quantitative performance indices are evaluated to support this claim. The validity of this approach is given a further proof by comparing the results with those obtained by using a WSN discrete event simulator. | non-battery |
Tin (IV) oxide, SnO2 films have been successfully synthesized in argon gas using a magnetron sputtering device. The morphology, structure, optical, photoluminescence, and photoresponse features of the samples have been analyzed via field electron scanning electron microscope, X-ray diffractograms, UV–Vis spectrometer, and spectro fluorophotometer. Compact nano grained morphologies with tetragonal structure and high absorbance were obtained. Increasing the annealing temperature led to a slight rise in the bandgap energies of the deposited samples. SnO2 films exhibited good photoluminescence features with increasing photoresponse with time as the annealing temperature reduced. The films can be potentially applied to optical and solar cell devices. | non-battery |
This paper introduces the 2012 round of the Egypt Labor Market Panel Survey (ELMPS), a publicly-available nationally representative longitudinal household survey. We describe the key characteristics of the ELMPS, including the samples and questionnaires for each round. Additionally, we examine the attrition processes observed in the panel and discuss the creation of weights to correct for attrition. We compare our data to other statistical sources for Egypt to evaluate the sample’s representativeness. To demonstrate how the ELMPS allows for an improved understanding of the labor market, we compare unemployment trends using the ELMPS and other data on unemployment in Egypt. | non-battery |
Solution processing via roll-to-roll (R2R) coating promises a low cost, low thermal budget, sustainable revolution for the production of solar cells. Poly[(5,6-difluoro-2,1,3-benzothiadiazol-4,7-diyl)-alt-(3,3′′′-di(2-octyldodecyl)-2,2′;5′,2′′;5′′,2′′′-quaterthiophen-5,5-diyl)], PffBT4T-2OD, has recently been shown to achieve high power conversion efficiency (>10%) paired with multiple acceptors when thick films are spun-coat from hot solutions. We present detailed morphology studies of PffBT4T-2OD based bulk heterojunction films deposited by the volume manufacturing compatible techniques of blade-coating and slot-die coating. Significant aspects of the film morphology, the average crystal domain orientation and the distribution of the characteristic phase separation length scales, are remarkably different when deposited by the scalable techniques vs. spun-coat. Yet, we find that optimized blade-coated devices achieve PCE > 9.5%, nearly the same as spun-coat. These results challenge some widely accepted propositions regarding what is an optimal BHJ morphology and suggest the hypothesis that diversity in the morphology that supports high performance may be a characteristic of manufacturable systems, those that maintain performance when coated thicker than ≈200 nm. In situ measurements reveal the key differences in the solidification routes for spin- and blade-coating leading to the distinct film structures.
| battery |
Potassium-ion batteries are attracting great attention as a promising alternative to lithium-ion batteries due to the abundance and low price of potassium. Herein, the phosphorus/carbon composite, obtained by a simple ball-milling of 20 wt% commercial red phosphorus and 80 wt% graphite, is studied as a novel anode for potassium-ion batteries. Considering the high theoretical specific capacity of phosphorus and formation of stable phosphorus-carbon bond, which can alleviate the volume expansion efficiently, the phosphorus/carbon composite exhibits a high charge capacity of 323.5 mA h g−1 after 50 cycles at a current density of 50 mA g−1 with moderate rate capability and cycling stability. By the X-ray diffraction analysis, the alloying–dealloying mechanism of phosphorus is proposed to form a KP phase. Meanwhile, prepotassiation treatment is conducted to improve the low initial coulomb efficiency. | battery |
We report the first attempt to retard the pulverization of an amorphous Li12Si7 anode by controlling the working voltage window. The suitable working voltage window for the amorphous Li12Si7 anode was determined to be 0.11−0.7V by analyzing the change in the charge transfer resistance using electrochemical impedance spectroscopy. After 100 cycles, the capacity retention of the Li12Si7 electrode cycled at 0.11−0.7V increased to 57.6% from the 18.2% capacity retention obtained for the electrode cycled at 0.02−2.0V, representing more than a 2-fold enhancement. SEM observations displayed the limited pulverization and fracture for the electrode cycled at 0.11-0.7V, which is the most important reason for the improved cycling stability. The methodology presented in this work can be extended to other electrode materials for Li-ion batteries that undergo large volume changes during lithiation/delithiation. | battery |
The design of Li-ion batteries with high energy storage capacities and efficiencies is a subject of increased research interest, being of key importance for their large-scale applications and further commercialization. However, conventional Li-ion batteries are expensive and have stability-related concerns, which limit their practical applications. In our search for cheaper and safer Li-ion batteries, we use a concentration gradient method to prepare LiNi0.9Co0.1–x Ti x O2 (0.02 ≤ x ≤ 0.05) cathode materials surface-enriched with Co and Ti that exhibit decreased oxygen loss and improved structural stability. The corresponding crystal structures and morphologies are analyzed by X-ray diffraction and field emission scanning electron microscopy, with the Ni, Co, and Ti concentration distributions determined by energy-dispersive X-ray spectroscopy. The material with the best performance (x = 0.04) exhibits a discharge capacity of 214 mAh g−1 in a charge/discharge voltage range of 3.0–4.3 V (vs. Li/Li+), and possesses an excellent 50-cycle capacity retention of 98.7%. Thermogravimetric analysis shows that partial substitution of Ni with the strongly oxophilic Ti solves the problem of oxygen loss observed in Ni-rich cathode materials such as LiNiO2. | battery |
Flexible supercapacitors with excellent performance are needed to meet the increasing demand for wearable and flexible electronics. The challenge remains to design exceptionally flexible supercapacitors with remarkable electrochemical properties. Natural nacre shows outstanding fracture toughness due to its alternating inorganic and organic layered structure and abundant interfacial interactions, providing an inspiration for designing flexible supercapacitors. Herein, we demonstrated nacre-inspired flexible supercapacitors via synergistic interfacial interactions of π-π conjugated bonds, hydrogen bonding, and electrostatic interaction between halloysite (HA)-polyaniline (PANI) nanocomposites and graphene oxide (GO) nanosheets. The resultant nacre-inspired HPA-rGO nanocomposite films demonstrate strong tensile strength (351.9 MPa), high electrical conductivity (397.0 S cm−1), and long cycle life with ~ 85% of capacitance retention after 10,000 cycles. Furthermore, the assembled all-solid-state supercapacitors (ASSSs) based on bioinspired HPA-rGO electrodes can not only display extraordinary flexibility with no decay of capacitance behavior after 5000 bending cycles, but also deliver remarkable mass energy density up to 16.3 Wh kg−1, outperforming other flexible graphene-based supercapacitors. This nacre-inspired strategy for designing flexible electrodes provides an avenue for the next-generation power source in the fields of aerospace and smart wearable electronics. | battery |